Method of controlling electric motors or other electrical translating devices.



No. 690,807. Patented Jan. 7, I902.

a. T. wouns. Y

METHOD OF OONTROLLING ELECTBIC MOTORS OR OTHER ELECTRICAL TRANSLATTNGDEVICES.

(Application filed Aug. 27, 1892.)

(No Model.)

w: NORRIS Ptrzns 00.. PHDTDLjYHm. WASHINGTON. a. 04

UNITED- STAT-ES PATENT OFFICE.

GRANVILLE '1. ooDS,-oF PARKRIDGE, NEW JERSEY, ASSIGNOR, BY MESNEASSIGNMENTS, T HARRY WARD LEONARD, or EAST ORANGE, NEW

JERSEY.

METHOD OF CONTROLLING ELECTRIC MOTORS OR OTHER ELECTRICAL TRANSLATINGDEVICES.

SPECIFICATION forming part of Letters Patent No. 690,807, dated January'7, 1902.

To aZZ whom it may concern.- Beit known that I, GRANVILLE T.WOODS, acitizen of the United States, residing at Park- 'ridge, in the county ofBergen and State of New Jersey, (formerly residing at New York city, inthe county and State of New York,) have invented certain new and usefulImprovements in the Method of Controlling Electric Motors or otherElectrical Translatro ing Devices, of which the following is aspecification.

The object of my invention is to provide for the efficient and economicregulation of electric motors or other translating devices I 5 withoutemploying regulating resistances in the manner in which they are nowused.

The invention consists, first, in an improved method ofcontrollingelectric motors by generating exterior to the motor to begoverned an electromotive'force counter to the current supplied to themotor from the main source and Varying such counter electromotive forceto control the supply of current from the main source to the motor;second, the above method of operation supplemented by the further stepof supplying to the motor to be governed an auxiliary current generatedby means of the energyemployed in developing said counter electromotiveforce, and, third, an improved organization of apparatus for carryingout the invention.

The accompanying drawing is a diagram illustrating my invention in asimple and efficient form. 3 5 The invention is shown applied to atrolley system of electrical propulsion.

A indicates the conductor upon which the trolley B runs, and M indicatesthe other side of the circuit, in this instance shown as the earth.

C indicates a switch by which the circuit connection between theapparatus and the conductor A may be opened and closed at pleasure.Current from the main circuit axle.

Application filed August 27. 1892. Serial No. 444,268. (No model) thecoil or coils -of the field-magnet G of an auxiliary motor, of which Eis the armature, and thence by wire 2 to earth. Current also passes fromthe conductor A through the switch 0, movable over a series ofresistances K, through the coil or coils of the field-magnet F of adynamo electric generator, of which D is the armature, and thence bywire 2 to earth. The wire 3 is connected from apoint X, between theconductor A and the coil of the field-magnet G, with one brush of thearmature E of said magnet, the other brush of which is connected by wire4 with a'brush 6 of the generator F D ;and a brush 7 of the mo- 6 tor IH to be controlled. The other brush 8 of Said motor is connected by wire11 with the remaining brush of the generator, and the two last-namedbrushes are connected from the point 9 by wires 10 and 2 to earth.

The operation of this apparatus is as follows: The fields of the mainmotor, the auxiliary motor, and the generator are energized by thecurrent passing in the connections de- I scribed, and the amount ofcurrent passing to the field-coil of the generator may be regulated bythe manipulation of the switch 0. The current from the conductor Areaches the armature H of the main motor after having traversed thearmature of the auxiliary 8o motor-4n other words, these armatures arein series. The current developed in the armature of the generator alsotraverses the armature of the main motor, these two armatures also beingin series. The apparatus will be running with the least expenditure ofenergy when the greatest resistance at O K is included in the circuit ofthe generaton field. As this resistance is cut down more currenttraverses said field and its magnetization is increased, or, in otherwords, the number of lines of force is increased.- This requires morework from the auxiliary motor G E, and as a consequence its speed isreduced, the counter electromotive force in its 5 armature-coils falls,and more current passes from the point X through the armature E, andconsequently through wire 4 and armature H to earth. At the Same timethe current developed in the armature of the generator F D is increased,and this current also traverses the armature H. The generator is sowound and constructed as to develop a current of a higher electromotiveforce than the main current taken from the conductor A.

The armature E is wound with a coarse wire to allow a large volume ofcurrent to pass through it without heating.

By this apparatus and method of operation I am enabled to dispense withordinary resistance regulators which absorb a large amount of power andare for other reasons objectionable.

The particularorganization illustrated may of course be varied and theinvention embodied in other forms of apparatus without departing fromthe principles thereof.

I do not claim herein the combination of apparatus and circuitconnections employed in carrying out the method of my invention, sincethose features are made the subject of a divisional application filedthe 28th day of March, 1901, Serial No. 53,212.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is as follows:

1. The method of controlling electric motors which consists in supplyingto the motor a current of electricity, and producing, by magneticinduction in the circuit between the source of supply and the motor, avariable magnetically-induced counter electromotive force independentlyof that of the motor, substantially as set forth.

2. The method of controlling electric motors which consists in supplyingto the motor a current of electricity, and producing by magneticinduction in the circuit between the source of supply and the motor avariable magnetically-induced counter electromotive force independentlyof that of the motor and opposing the current from the source of supply,substantially as set forth.

3. The herein-described method of regulating an electric motor, whichconsists in inductively developing exterior thereto and in the circuitthereof a counter electromotive force opposing the main current, varyingelectric motor, which consists in placing in series with its armaturethe armature of a dynamo-electric machine generating by dynamicinduction in the armature of said dynamo-electric machine a counterelectromotive force and varying the counter electromotive force sogenerated, substantially as set forth.

5. The method of varying the electromotive force at the terminals of atranslating device, which consists in developing in series with thetranslating device by means of arevolving winding an electromotive forcebetween the source of supply and the translating device which isvariable at will, substantially as set forth.

6. The method of generating and regulating the supply of electricenergyto translating devices, which consists in generating current, passingsame into a multiple-arc distribution system and through a source ofvariable electromotive force, and causing the electromotive force of thevariable source to oppose the electromotive force of the source ofsupply, substantially as set forth.

'7. The method of obtaining from a source of electromotive force adiiferent and controllable electromotive force at the terminals of atranslating device with a minimum waste of energy, consisting in placingin the path of the current leading to the translating device thearmature of a dynamo-electric machine, and operating said machine as amotor to reduce the electromotive force at the terminals of thetranslating'device, substantially as set forth.

In testimony whereof I have hereunto subscribed my name.

GRANVILLE T. WOODS.

Witnesses:

FRANK S. OBER, EDWARD O. DAVIDSON.

